Analgesia induced by brief footshock: blockade by fenfluramine and 5-methoxy-N,N-dimethyltryptamine and prevention of blockade by 5-HT antagonists.
Brain research November 21, 1983 P H Hutson, M D Tricklebank, G Curzon 13 citations
Analgesia caused by a brief footshock in rats is reduced by drugs that increase serotonin (5-HT) activity—fenfluramine, which releases serotonin, and 5-MeODMT, a fast-acting serotonin agonist. These reductions are blocked by serotonin antagonists cyproheptadine and methiothepin, but those antagonists alone do not affect the shock-induced pain relief. Thus, the natural analgesia from brief footshock likely does not rely on serotonin mechanisms, though it can be altered by pharmacologically boosting serotonin. 5-MeODMT could also weaken analgesia after it starts, possibly by disrupting memory rather than pain processing directly.